1. Field of the Invention
A method of producing a clouding agent from citrus membrane and/or peel for use in fruit juices and soft drink beverages.
2. Description of Prior Art
Consumers expect fruit juices and beverages to be cloudy rather than clear. Cloudy beverages and soft drinks achieve cloudiness by adding a natural or chemical ingredient such as titanium dioxide or brominated vegetable oil. Usually these substances are not in citrus beverages and the use of brominated vegetable oil has been regulatorily curtailed. Curtailment has resulted in a need to find a substitute beverage cloud.
All citrus juices, when freshly expressed, have a characteristic opacity of cloudiness. It is obviously desirable to maintain this opacity in processing citrus juices, and to emulate it in formulated citrus beverages. In the natural juices, "cloud" is provided by minute suspended or colloidal particles of citrus tissue and cell contents.
In formulated beverages, cloudiness is achieved by adding a suitable natural or chemical substance, such as titanium dioxide or brominated vegetable oil. Usually these substances are alien to citrus beverages. In keeping with the current consumer emphasis on natural ingredients, several efforts have been directed toward developing a clouding agent from citrus peel or citrus albedo.
U.S. Pat. No. 4,388,330 relates to the cloud stability of citrus juice beverages and beverage bases by subjecting pasteurized concentrated or single strength citrus juice to at least one enzyme having protease activity. The juice may be pretreated mechanically or enzymatically to enhance protease activity prior to or simultaneously with treatment with at least one enzyme having protease activity.
U.S. Pat. No. 3,647,475 teaches a cloud fortified citrus fruit juice product adding a quantity of finely divided albedo, or inner white layer of the rind or peel of the citrus fruit from which the outer flavedo layer containing the oil has been removed to an extracted fruit juice.
WO 94/27451 shows a process for preparing natural thickeners derived from citrus fruit for beverages. The process comprises the steps of preparing a slurry of water and citrus pulp, heating the slurry and subjecting the slurry to high shear.
FR 2,590,123 teaches a product able to produce a stable, turbid phase in fruit juices from the complete peel of a citrus fruit or only the albedo portion of the peel by bleaching in presence of citric acid.
U.S. Pat. No. 2,556,579 discloses a process for the treatment of citrus peel by subjecting the peel to disintegrating and wet washing operations to remove the bulk of bitter skin components and to provide a hydrous pulp for further treatment, heating the material while subjected it to a partial vacuum with agitation, adding sugar to the material and then subjecting the material to milling to disperse pockets of bitter components.
U.S. Pat. No. 4,335,143 shows a process for producing a dried albedo clouding agent which does not impart off-flavors to the beverage. The process involves heating albedo-containing material which is then ground and treated with a macerating enzyme. The enzyme is then inactivated and coarse particles are filtered out and discarded. The filtrate is centrifuged to obtain the clouding agent which is then washed with water, isopropyl alcohol or a combination of the two. The clouding agent is dried to obtain a stable product compatible with dry beverage formulas for citrus-type beverages.
U.S. Pat. No. 3,404,990, discloses a procedure whereby citrus peels are comminuted, heated and then enzyme treated to facilitate the extraction of clouding material. The entire mixture is briefly centrifuged to remove the pulp and the supernatant liquid is pasteurized. Excess water is then evaporated. The final clouding agent product is a liquid concentrate.
FR 2,331,292 describes a procedure which is basically similar, but the citrus albedo is sieved, milled and homogenized in such a way as to minimize the amount of pulp discarded, and no enzyme is added. The final clouding agent is a liquid concentrate which has the consistency of fresh cream.
Matthews, Herrera and Crandall of the University of Florida have recently developed a procedure wherein a clouding agent is obtained from the water which has been used to leach citrus peel during pectin or dietary fiber production. The final clouding agent is a liquid concentrate differing from the previous examples in that it is free of pectin and contains soluble carbohydrates as the major component.
Further examination of the literature leads to the conclusion that all prior procedures ultimately produce a liquid concentrate which consists of cloud particles and varying amounts of soluble carbohydrates, and with the exception of the Matthews procedure pectinaceous material. Bradock and Kesterson, from the University of Florida, have evaluated typical prior art clouding agents in their article "use of Enzymes in Citrus Processing" Food Technology, November 1979. They report that the cloud may be quite bitter; the cloud concentrate has a tendency to brown or darken with storage; and the clouding ability of the concentrate varies with each batch of peel, which would make standardization of the cloud level in the final beverage extremely difficult.
Additional examples of the prior art are found in U.S. Pat. No. 2,935,407; U.S. Pat. No. 3,112,202; U.S. Pat. No. 3,660,105; U.S. Pat. No. 4,371,552; U.S. Pat. No. 5,202,142; RU 2,004,162; FR 2,520,983 and JP 59-162,860.